[Dfariswheel]

Because I specialized in doing Colt work for the trade, I saw mostly Colt's.
I saw a fair number of S&W's, fewer Ruger's and few Dan Wesson's.

Here's my take on the plus and minuses.

The Colt's were always "consistently" more accurate then S&W, Ruger, or Dan Wesson.
This accuracy was due to Colt's higher grade barrels and the old Colt action that locks the cylinder tightly in alignment with the bore at the moment of ignition.
This is simply a matter of mechanics. When the bullet enters the bore perfectly centered like with the Colt, the bullet gets distorted less and is more accurate.
Later models like the Trooper Mark III/King Cobra, Anaconda were accurate because of Colt's factory-made barrels, faster twist rifling, and all around quality of the gun.

S&W accuracy fluctuated, with one gun being very accurate, another not too good, but on average S&W accuracy was good.

Ruger accuracy fluctuates wildly.
Seeing a less than accurate Ruger is not unusual, and carries all across the Ruger product line.
You'll see VERY accurate Ruger firearms, and the next one will just not shoot.

While the Dan Wesson was noted for accuracy, their problem was the quality fluctuated so badly, you couldn't count on getting an accurate one.

Colt always seemed to do a better job of where they spent their money.
Colt was always a step above S&W in actual overall quality.
The Colt's were nicely finished outside, and nicely finished inside, with fewer burrs and machine marks.
S&W seemed to spend most of their dollar on the outside for a nice blue job, but inside was usually rougher than Colt.

Ruger was always rougher inside and out, but as with all cast steel guns, the actual working surfaces were about as smooth as they could be as-is.

Dan Wesson fluctuated wildly depending on their business health at the moment.

Colt's frame and cylinder was stronger than S&W or Ruger.
Colt's frame and cylinder were higher quality forgings, and the off-set cylinder notches made the cylinder stronger.
Fact is, even the S&W 686 was slightly less strong then the Colt due to their cylinder notches right over the chamber.

Ruger has a more massive frame, but that's because they HAD to be more massive to provide as strong a frame from castings.
The later Colt's like the Trooper Mark III/King Cobra was probably the strongest medium frame DA revolvers ever made, INCLUDING the later Ruger GP-100 and S&W 686.

The old Colt action is far more intricate, has much smaller operating surfaces, and smaller parts.
The action is complex and very difficult to work on.
It won't take the abuse the later Colt's, the S&W, and the Ruger will.

The last of the old Colt's was the Python, and it was a true semi-custom built gun.
All the older Colt's parts were made over-sized and stoned and filed to fit by a Master fitter, then the parts were adjusted for perfect operation.
The Python went even farther with extensive hand polishing and tuning for perfect operation.
This hand labor priced it out of the market.
Up side of all this was a better quality gun, with more potential accuracy.
Down side was, it won't take the abuse the S&W and Ruger will take and keep operating correctly.

S&W has the easiest action to tune, and most shooters prefer the S&W "feel" over the Colt, unless they've taken the time to "learn" the Colt action.
Colt parts that are worn can often be refitted.
The newer Colt's, S&W, and Ruger are intended to have worn parts just replaced with new parts.

Bottom Line:
The older Colt's were the best quality and most consistently accurate. This includes less expensive models like the Official Police, Detective Special, etc, not just the Python.

S&W was close behind, but "on average" just a little less accuracy than Colt's because of the action design, not quality issues.

Ruger is a good step below S&W in overall quality, with inconsistent accuracy, but.... is considered to be the "best buy" for the average shooter.

Dan Wesson is below Ruger in quality.
Shiny blue jobs, but often with a reddish color indicative of used up or improperly controlled bluing operation.
Dan Wesson accuracy was Python-good when it was good, and lousy whenever their quality fell just before yet another bankruptcy.

NOTE: I'm not discussing INDIVIDUAL guns.
I've seen Pythons that wouldn't shoot well, and Ruger's that shot as well as any revolver I've ever seen.
What I'm talking about is "on the average".
In other words, take 50 new Colt Official Police revolvers and shoot them against 50 new S&W Model 10 revolvers.

One revolver (A Colt or a S&W) will be the most accurate.
One revolver will be the LEAST accurate.
"On the average" of the 100 guns, the Colt's will be more accurate.

I base this on 30 years and the thousands of revolvers I've seen.